tests/acceptance/machine_sparc_leon3: Disable HelenOS test

This test was written/tested around beginning of 2019, but was
extracted from a bigger series and posted end of June 2019 [*].
Unfortunately I did not notice commit 162abf1a8 was merged by
then, which implements the AHB and APB plug and play devices.

HelenOS 0.6 is expecting the PnP registers to be not implemented
by QEMU, then forces the discovered AMBA devices (see [2]).

Before 162abf1a8, the console was displaying:

  HelenOS bootloader, release 0.6.0 (Elastic Horse)
  Built on 2014-12-21 20:17:42 for sparc32
  Copyright (c) 2001-2014 HelenOS project
   0x4000bf20|0x4000bf20: kernel image (496640/128466 bytes)
   0x4002b4f2|0x4002b4f2: ns image (154195/66444 bytes)
   0x4003b87e|0x4003b87e: loader image (153182/66437 bytes)
   0x4004bc03|0x4004bc03: init image (155339/66834 bytes)
   0x4005c115|0x4005c115: locsrv image (162063/70267 bytes)
   0x4006d390|0x4006d390: rd image (152678/65889 bytes)
   0x4007d4f1|0x4007d4f1: vfs image (168480/73394 bytes)
   0x4008f3a3|0x4008f3a3: logger image (158034/68368 bytes)
   0x4009feb3|0x4009feb3: ext4fs image (234510/100301 bytes)
   0x400b8680|0x400b8680: initrd image (8388608/1668901 bytes)
  ABMA devices:
  <1:00c> at 0x80000100 irq 3
  <1:00d> at 0x80000200
  <1:011> at 0x80000300 irq 8
  Memory size: 64 MB

As of this commit, it is now confused:

  ABMA devices:
  <1:3000> at 0x00000000 irq 0
  <1:3000> at 0x00000000 irq 0
  <1:3000> at 0x00000000 irq 0
  <1:3000> at 0x00000000 irq 0
  <1:3000> at 0x00000000 irq 0
  <1:3000> at 0x00000000 irq 0
  <1:3000> at 0x00000000 irq 0
  ...

As this test is not working as expected, simply disable it (by
skipping it) for now.

[1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg627094.html
[2] https://github.com/HelenOS/helenos/blob/0.6.0/boot/arch/sparc32/src/ambapp.c#L75

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200331105048.27989-2-f4bug@amsat.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
diff --git a/tests/acceptance/machine_sparc_leon3.py b/tests/acceptance/machine_sparc_leon3.py
index f77e210..2405cd7 100644
--- a/tests/acceptance/machine_sparc_leon3.py
+++ b/tests/acceptance/machine_sparc_leon3.py
@@ -7,12 +7,16 @@
 
 from avocado_qemu import Test
 from avocado_qemu import wait_for_console_pattern
+from avocado import skip
 
 
 class Leon3Machine(Test):
 
     timeout = 60
 
+    @skip("Test currently broken")
+    # A Window Underflow exception occurs before booting the kernel,
+    # and QEMU exit calling cpu_abort(), which makes this test to fail.
     def test_leon3_helenos_uimage(self):
         """
         :avocado: tags=arch:sparc